you will need to increase the vcore when it isnt stable or stops booting. you only want to do it in small incriments. i dont know the default vcore but u dont want to go much over 1.5 volts. you should also read the sticky on ocing intels. hope this helps

Increasing vcore comes when you are not stable at a higher then stock FSB. Just becuase windows loads up and you can listen to mp3s, surf the web, etc doesnt really mean your oc is stable. Running programs like OCCT and Prime 95 to stress the system considerably will let you know for sure if your stable.. F@H with Prime95 is a good combination to test for stability it ensures 100% cpu load and will max out your temps so you can see your hightest max cpu temp. You dont want that prescott to be more then 65*C at max load temp. You should run prime95 for around 12 hrs to test for stability usually if there are any errors they happen within the first 15-30 minutes of running prime95. The 12 hours of running prime95 is preferred by almost everyone on these forums. Also thats a nice beginning OC you have there and good luck with getting it higher.